Figure 2: The cargo quenches the nanophores’ magnetic properties.

Loading nanophores with cargo increased the T2 (a) and T1 (b) ([Fe])=10 μg ml⁻¹; mean±s.e.m., n=3). The nanoparticles were first dialyzed to remove any unloaded compound, followed by relaxation measurements. (c) The gradual addition of Flutax1 within Ferumoxytol’s coating increased the nanoparticle formulation’s T2 and T1 signal (linear regression correlation coefficients r_T2=0.98 and r_T1=0.94; [Fe]=10 μg ml⁻¹; mean±s.e.m., n=3). (d,e) The incorporation of cargo within the nanophores’ coating resulted in changes on the nanoparticles’ relaxivities (mean±s.e.m., n=3). (f) The change in relaxivity (Δr₂) was associated with the drug’s solubility in DMSO (linear regression correlation coefficient r=0.90; mean±s.e.m., n=3; solubility information was obtained from Selleck Chemicals). (g) MRI phantom images of unloaded and loaded Ferumoxytol, demonstrating that the cargo does not affect the nanoparticles’ T2* signal, as opposed to its effect on T2 (iron concentrations: high=10 μg ml⁻¹, medium=6 μg ml⁻¹ and low=4 μg ml⁻¹).